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Overview
Comment: | Smaller and faster implementation of the fillInCell() routine. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA3-256: |
77074990edef6c42bdfe7ccce1affc8e |
User & Date: | drh 2017-08-23 14:45:59.667 |
Context
2017-08-23
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20:36 | Size and performance optimization to dropCell() and freeSpace(). (check-in: bc1ec123ce user: drh tags: trunk) | |
14:45 | Smaller and faster implementation of the fillInCell() routine. (check-in: 77074990ed user: drh tags: trunk) | |
2017-08-22
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21:23 | Update documentation to make it clear that SQLITE_SOURCE_ID and sqlite3_sourceid() might changes if the source code is edited. (check-in: e69c0c8770 user: drh tags: trunk) | |
Changes
Changes to src/btree.c.
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6214 6215 6216 6217 6218 6219 6220 | MemPage *pPage, /* The page that contains the cell */ unsigned char *pCell, /* Complete text of the cell */ const BtreePayload *pX, /* Payload with which to construct the cell */ int *pnSize /* Write cell size here */ ){ int nPayload; const u8 *pSrc; | | < | | | | > > > | | > > > > | > > > | | | | | | | | < > | > | 6214 6215 6216 6217 6218 6219 6220 6221 6222 6223 6224 6225 6226 6227 6228 6229 6230 6231 6232 6233 6234 6235 6236 6237 6238 6239 6240 6241 6242 6243 6244 6245 6246 6247 6248 6249 6250 6251 6252 6253 6254 6255 6256 6257 6258 6259 6260 6261 6262 6263 6264 6265 6266 6267 6268 6269 6270 6271 6272 6273 6274 6275 6276 6277 6278 6279 6280 6281 6282 6283 6284 6285 6286 6287 6288 6289 6290 | MemPage *pPage, /* The page that contains the cell */ unsigned char *pCell, /* Complete text of the cell */ const BtreePayload *pX, /* Payload with which to construct the cell */ int *pnSize /* Write cell size here */ ){ int nPayload; const u8 *pSrc; int nSrc, n, rc, mn; int spaceLeft; MemPage *pToRelease; unsigned char *pPrior; unsigned char *pPayload; BtShared *pBt; Pgno pgnoOvfl; int nHeader; assert( sqlite3_mutex_held(pPage->pBt->mutex) ); /* pPage is not necessarily writeable since pCell might be auxiliary ** buffer space that is separate from the pPage buffer area */ assert( pCell<pPage->aData || pCell>=&pPage->aData[pPage->pBt->pageSize] || sqlite3PagerIswriteable(pPage->pDbPage) ); /* Fill in the header. */ nHeader = pPage->childPtrSize; if( pPage->intKey ){ nPayload = pX->nData + pX->nZero; pSrc = pX->pData; nSrc = pX->nData; assert( pPage->intKeyLeaf ); /* fillInCell() only called for leaves */ nHeader += putVarint32(&pCell[nHeader], nPayload); nHeader += putVarint(&pCell[nHeader], *(u64*)&pX->nKey); }else{ assert( pX->nKey<=0x7fffffff && pX->pKey!=0 ); nSrc = nPayload = (int)pX->nKey; pSrc = pX->pKey; nHeader += putVarint32(&pCell[nHeader], nPayload); } /* Fill in the payload */ pPayload = &pCell[nHeader]; if( nPayload<=pPage->maxLocal ){ /* This is the common case where everything fits on the btree page ** and no overflow pages are required. */ n = nHeader + nPayload; testcase( n==3 ); testcase( n==4 ); if( n<4 ) n = 4; *pnSize = n; assert( nSrc<=nPayload ); testcase( nSrc<nPayload ); memcpy(pPayload, pSrc, nSrc); memset(pPayload+nSrc, 0, nPayload-nSrc); return SQLITE_OK; } /* If we reach this point, it means that some of the content will need ** to spill onto overflow pages. */ mn = pPage->minLocal; n = mn + (nPayload - mn) % (pPage->pBt->usableSize - 4); testcase( n==pPage->maxLocal ); testcase( n==pPage->maxLocal+1 ); if( n > pPage->maxLocal ) n = mn; spaceLeft = n; *pnSize = n + nHeader + 4; pPrior = &pCell[nHeader+n]; pToRelease = 0; pgnoOvfl = 0; pBt = pPage->pBt; /* At this point variables should be set as follows: ** ** nPayload Total payload size in bytes ** pPayload Begin writing payload here ** spaceLeft Space available at pPayload. If nPayload>spaceLeft, ** that means content must spill into overflow pages. |
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6292 6293 6294 6295 6296 6297 6298 | assert( info.nKey==pX->nKey ); assert( *pnSize == info.nSize ); assert( spaceLeft == info.nLocal ); } #endif /* Write the payload into the local Cell and any extra into overflow pages */ | | > > > > > > > > > > > > > > > > > > > > > > > > > > > | 6302 6303 6304 6305 6306 6307 6308 6309 6310 6311 6312 6313 6314 6315 6316 6317 6318 6319 6320 6321 6322 6323 6324 6325 6326 6327 6328 6329 6330 6331 6332 6333 6334 6335 6336 6337 6338 6339 6340 6341 6342 6343 6344 | assert( info.nKey==pX->nKey ); assert( *pnSize == info.nSize ); assert( spaceLeft == info.nLocal ); } #endif /* Write the payload into the local Cell and any extra into overflow pages */ while( 1 ){ n = nPayload; if( n>spaceLeft ) n = spaceLeft; /* If pToRelease is not zero than pPayload points into the data area ** of pToRelease. Make sure pToRelease is still writeable. */ assert( pToRelease==0 || sqlite3PagerIswriteable(pToRelease->pDbPage) ); /* If pPayload is part of the data area of pPage, then make sure pPage ** is still writeable */ assert( pPayload<pPage->aData || pPayload>=&pPage->aData[pBt->pageSize] || sqlite3PagerIswriteable(pPage->pDbPage) ); if( nSrc>=n ){ memcpy(pPayload, pSrc, n); }else if( nSrc>0 ){ n = nSrc; memcpy(pPayload, pSrc, n); }else{ memset(pPayload, 0, n); } nPayload -= n; if( nPayload<=0 ) break; pPayload += n; pSrc += n; nSrc -= n; spaceLeft -= n; if( spaceLeft==0 ){ MemPage *pOvfl = 0; #ifndef SQLITE_OMIT_AUTOVACUUM Pgno pgnoPtrmap = pgnoOvfl; /* Overflow page pointer-map entry page */ if( pBt->autoVacuum ){ do{ pgnoOvfl++; } while( PTRMAP_ISPAGE(pBt, pgnoOvfl) || pgnoOvfl==PENDING_BYTE_PAGE(pBt) |
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6346 6347 6348 6349 6350 6351 6352 | releasePage(pToRelease); pToRelease = pOvfl; pPrior = pOvfl->aData; put4byte(pPrior, 0); pPayload = &pOvfl->aData[4]; spaceLeft = pBt->usableSize - 4; } | < < < < < < < < < < < < < < < < < < < < < < < < | 6383 6384 6385 6386 6387 6388 6389 6390 6391 6392 6393 6394 6395 6396 | releasePage(pToRelease); pToRelease = pOvfl; pPrior = pOvfl->aData; put4byte(pPrior, 0); pPayload = &pOvfl->aData[4]; spaceLeft = pBt->usableSize - 4; } } releasePage(pToRelease); return SQLITE_OK; } /* ** Remove the i-th cell from pPage. This routine effects pPage only. |
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